Modular integrated self-contained cargo deployment/retrieval system

ABSTRACT

The present invention relates to a self contained, modular integrated deployment and retrieval system for use with an aircraft such as a helicopter. The deployment and retrieval system comprises a support frame, a winch connected to the support frame, a tow cable wound around the winch, which tow cable is connected to the external load, and a support structure connected to the support frame. The support structure is axially movable relative to the support frame for moving the external load so as to control the center of gravity of the aircraft and so as to deploy and retrieve the external load.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a system and a method for moreefficiently deploying and retrieving large external loads from anaircraft, such as a helicopter.

[0002] Currently, the U.S. Navy and the Japanese Maritime Self Defenseforce deploy and retrieve airborne mine counter measures (AMCM)equipment using a system 10 such as that shown in FIG. 1. The system 10includes a tow boom 12, a winch 14, a davit 16, a cradle 18, a modifiedaircraft ramp 20 capable of moving from an up and closed position to a90 degree (vertically down) open position, and an aperture guard 19.Airborne mine counter measure deployment and retrieval operations areperformed as follows. The tow boom 12 is moved from its center linestowed position to a side stow position. The winch cable 22 is unwoundfrom the winch 14 aft to the davit sheave 24. The davit sheave cableretainer is opened and the cable 22 is laid on the sheave 24 and lockedin place by closing the davit cable retainer. The cable 22 is then runto and attached to the towed body 28. The towed body 28 is unstrappedfrom its transport cradle 18. The davit 16 is rotated aft from itsstowed forward position while the winch 14 is then activated, liftingthe towed body 28 from its cradle 18. At the same time, the ramp 20 islowered to further increase the clearance between the cradle 18 and thetowed body 28. Continuous rotation aft of the davit 16 is maintained asthe ramp 20 is now also lowered until the towed body 28 fully clears theramp 20 and the cradle 18. The towed body 28 is then further lowereduntil it enters the water by a synchronous operation of the winch 14 andthe davit 16. A tow ball is secured to the tow cable 22. The tow boom 12is rotated to the aircraft center line and lowered over the tow cable 22and the tow ball. The tow cable 22 is played off the winch 14 to trapthe tow ball in the tow hook 34. A guillotine is placed over the towcable 22 and secured to the aft facing end of the tow boom tow hook 34.The aircraft is now ready to begin tow operations. Towed body retrievalis the reverse of this procedure, with the additional crew task of usinga manually held pole to stabilize and correct the attitude of the towedbody 28 as it approaches the aircraft.

[0003] This prior art system is very inefficient and can have a largeweight impact on the basic aircraft. This prior art system also is verylabor intensive and has high risk tasks associated with it. Stillfurther, this prior art system requires extensive fuselagemodifications.

SUMMARY OF THE INVENTION

[0004] Accordingly, it is an object of the present invention to providea system and a method for deploying and retrieving large external loadsfrom an aircraft such as a helicopter.

[0005] It is a further object of the present invention to provide asystem and a method as above which is simpler to use.

[0006] It is still a further object of the present invention to providea system as above which is self-contained and modular in nature.

[0007] It is yet a further object of the present invention to provide adeployment and retrieval system which can be integrated into an existingaircraft structure with minimum structural modifications.

[0008] The foregoing objects are attained by the deployment andretrieval system and method of the present invention.

[0009] In accordance with the present invention, a system for deployingand retrieving an external load from an aircraft, such as a helicopter,broadly comprises a support frame, a winch connected to the supportframe, a tow cable wound around the winch, which tow cable is connectedto the external load, and a support structure connected to the supportframe. The support structure is axially movable relative to the supportframe for moving the external load so as to aid in deploying the load oraid in controlling the center of gravity of the aircraft.

[0010] Further, in accordance with the present invention, a method fordeploying and retrieving an external load from an aircraft broadlycomprises the steps of providing a self contained modular deployment andretrieval system which includes a support frame, a winch connected tothe support frame, and an axially movable support structure connected tothe support frame for supporting a sheave, passing a tow cable on thewinch over the sheave and connecting an end of the tow cable to theexternal load, and moving the support structure relative to the supportframe from a retracted position to a deployed position so that theexternal load passes through an opening in the aircraft.

[0011] Other details of the modular integrated self contained cargodeployment and retrieval system of the present invention, as well asother objects and advantages attendant thereto, are set forth in thefollowing detailed description and the accompanying drawings whereinlike reference numerals depict like elements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 illustrates a prior art system for deploying airborne minecounter measures;

[0013]FIG. 2 is a schematic representation of a modular integrated selfcontained cargo deployment and retrieval system in accordance with thepresent invention;

[0014]FIG. 3 is a schematic representation of the system of FIG. 2 movedfrom a retracted position to a deployed position;

[0015]FIG. 4 illustrates a tow boom which may be used with thedeployment and retrieval system of FIG. 2; and

[0016]FIG. 5 is a schematic representation of a mine hunting systemwhich utilizes the deployment and retrieval system of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0017] Referring now to FIGS. 2 and 3, a modular integrated selfcontained cargo deployment and retrieval system 50 in accordance with afirst embodiment of the present invention is illustrated. The deploymentand retrieval system 50 may be installed a wide variety of helicopters,each having a fuselage 48. The system 50 includes a modular structuralsupport frame 52 having side rails 54 and 56, end walls 58 and 60, andenergy absorbing member 62 extending between the side rails 54 and 56.The energy absorbing member 62 serves a number of functions. First, itstabilizes the support frame 52. Second, it acts as a forward crashrestraint for an external load 86 to be deployed and retrieved. Each ofthe side rails 54 and 56 is provided with a track 64 whose purpose willbe discussed hereinafter. The track 64 may take the form of alongitudinally extending slot such as that shown in FIGS. 2 and 3.Alternatively, each track 64 may be a top surface and/or a side surfaceof a respective side rail 54, 56. The support frame 52 and its variouscomponents may be formed from any suitable lightweight metallic,non-metallic, or composite materials known in the art.

[0018] The system 50 further includes an axially movable supportstructure 66 connected to the support frame 52. The support structure 66is movable along an axis 69 parallel to the center line 67 of theaircraft in which the system 50 is installed between the retracted anddeployed positions shown in FIG. 3. The axially movable supportstructure 66 includes side elements 68 and support arms 70 forsupporting a sheave 72. Each of the side elements 68 has engagementmeans 74 and 76, such as forward and aft rollers and slide elements (orpins), which cooperate with and move along the track 64. Positive motionand positioning of the support structure 66 is provided by theengagement means 74 and 76 cooperating with the track 64. The sideelements 68 and support arms 70 may be formed from any suitable metallicor non-metallic, or composite material known in the art.

[0019] The modular system 50 further includes a pair of actuators 78 formoving the support structure 66 relative to the support frame 52. Eachof the actuators 78 is connected at one end to the support frame 52 andat the other end to part of the support structure 66 such as one of theside elements 68. The actuators 78 may comprise any suitable hydraulicor electrically operated actuators known in the art. The actuators 78impart a linear movement to the support structure 66 that allows theexternal load 86 to be moved fore and aft in the aircraft for center ofgravity control as well as for deployment and retrieval. While a pair ofactuators 78 has been shown, if desired, only one actuator 78 may beprovided to move the support structure 66 relative to the support frame52. Alternatively, one may be use more than two actuators 78 if desired.

[0020] Also mounted to the support frame 52 is a winch 80. Any suitablemeans known in the art such as side arms 82 may be used to secure thewinch 80 to the support frame 52. Wound onto the winch 80 is a tow cable84. The tow cable 84 is attached at a first end to the winch 80 and at asecond end to the external load 86 to be deployed and retrieved. Theexternal load 86 may be a towed body such as one used in airborne minecounter measure operations, a rescue basket, fire fighting equipment, orequipment to be deployed at inaccessible topographical locations. Anotch or a raised support cradle structure 88 may be provided in the endwall 60 so that the external load 86 may rest and be secured in aretracted or transport position.

[0021] To make the system 50 truly modular, hydraulic or electriccontrols and operational monitoring equipment 90 are also mounted on thesupport frame 52. The controls 90 may include rotational and linearsensors and video cameras which synchronize linear motion of the sheave72 with motion of the winch 80. Synchronized sensing permits theexternal load 86 to remain captured to and controlled by the system 50.Controls 90 also permit operators to be safely displaced from possiblehazardous operations.

[0022] The system 50 may be installed in an aircraft fuselage using anysuitable means known in the art such as by shear and/or tensionconnections. When installed, the system 50 is preferably aligned so thatthe longitudinal axis 65 of the support frame 52 coincides with thecenter line 67 of the aircraft. Further, by securing the support frame52 in the shear planes of the floor and fuselage frames, complexfuselage modifications can be eliminated and excessive torsional andbending loads may be reduced.

[0023] In use, the support structure 66 is moved relative to the supportframe 52 via the actuators 78 from a retracted position to a deployedposition where the external load 86 is extended through an opening 81 inthe aircraft fuselage. The opening 81 can be a rear door opening on theaircraft. The winch 80 is then operated to deploy the external load 86via the tow cable 84. To retrieve the external load 86, the winch 80 isoperated to wind the tow cable 84 onto the winch 80. When the externalload 86 is above the level of the opening 81, the actuators 78 are thenoperated to again move the support structure 66 relative to the supportframe 52 from the deployed position to the retracted position. It shouldbe noted that when the support structure 66 is in its retractedposition, the sheave 72, the energy absorbing structure 62, and thenotched member or the raised cradle structure 88 provide crash restraintcapabilities for the external load 86 in all degrees of freedom.

[0024] If desired, the winch 80 may be connected to the support frame 52so that the winch moves forward and aft with the support structure 66.By providing such an arrangement, one can use the winch 80 to controlthe aircraft center of gravity during deployment and towing.

[0025] As shown in FIG. 3, a removable shield 92 may be secured over themodular system 50. The shield 92 may be formed from any suitableprotective material known in the art and may be secured to the frame 52using any suitable means known in the art. If desired in lieu of theshield 92, a barrier arrangement may be provided in front of the supportframe 52 to reduce noise, to reduce hazards, and to control theenvironment of the aircraft.

[0026] Referring now to FIG. 4, the system 50 may include a Y-shaped towboom 100 for capturing the tow cable 84 during deployment of theexternal load. The tow boom 100, in a preferred embodiment, has supportlegs 102 and 104 which may be pivotally connected to a portion of thesupport structure 66, such as the side elements 68. Each of the legs 102and 104 terminates in a tow ball capture device 106 which includes a towhook 124 and a pyrotechnic cable cutter 126. In a preferred embodiment,each leg 102 and 104 has a first leg portion 108 and a second legportion 110 connected to the first leg portion 108 by a hinge oruniversal joint connection 112. Each connection 112 preferably has alocked position and an unlocked position. Load cells and yaw sensors 114may be incorporated into either leg portion 108 or 110 of each supportleg 102 and 104 to provide automatic tow tension indication to preventoverloads. The pivotal connections 116 between the legs 102 and 104 andthe support structure 66 may include pitch sensors 118 to detect theangular position of the tow boom 100 relative to the aircraft. Ifdesired, one or more remote video cameras 122 may be mounted to the towboom 100 to provide visual surveillance of the tow boom 100.

[0027] When the external load 86 is in a transport or pre-deploymentmode, the tow boom 100 takes position A shown in FIG. 4. In thisposition, the tow boom 100 is retracted or located above the externalload 86. As the external load 86 is deployed, the tow boom 100 pivotsabout two horizontal axes defined by the pivotal connections 116 and theconnection(s) 112, thus enabling the tow boom 100 to move in a verticalplane. As the external load 86 is being deployed, the tow boom 100follows its downward motion, unfolds, and moves into the trussconfiguration shown in FIG. 4 as position B. The tow cable 84 is thussuspended through a cable control window 120 formed by the leg portions110, the tow hook 124 and the pivotal connections 112 of the tow boom100, thus eliminating any need for an aperture guard.

[0028] To engage the tow cable 84 in the tow hook 124 at the apex of thetow boom 100, the aircraft is transitioned to a tow mode which moves thetow cable 84 aft. This results in the tow cable 84 being trapped in thetow hook 124 by means of a cable diameter increasing device such as atow ball. The cable diameter increasing device prevents the cable 84from passing through the tow hook 124. At the same time, the pyrotechniccable cutter 126 surrounds the tow cable 84 in the event that it isneeded. To disengage the tow cable 84 during retrieval of the externalload 86, the winch 84 is activated. This pulls the cable diameterincreasing device of the tow cable 84 out of the tow hook 124. As theexternal load 86 is retracted, it automatically unlocks the connections112 when it contacts the tow boom, allowing the tow boom to fold andretract back to position A. If desired, the winch 80 may be used to foldand retract the tow boom 100.

[0029] The tow boom 100 can be manufactured from any suitablelightweight material, such as composite materials, to reduce its weight.

[0030] If desired, a containment device 128 may be affixed to the towboom 100 to protect the external load 86. The containment device 128 maybe formed from any suitable material.

[0031] The tow boom 100 forms a cable guide replacing the old apertureguards. This helps to automate the tow hook/tow ball arrangement andkeep cables away from the tail rotor of a helicopter. The tow boom 100can be made to automatically fold upon retrieval of the external load,thereby guiding the capture of the load and eliminating the manuallyheld pole of the old systems.

[0032] The system 50 of the present invention provides numerous otheradvantages. First and foremost, the system 50 is modular in nature andself-contained. In other words, all the components of the system neededto deploy and/or retrieve an external load 86 are provided in one unit.Other advantages to the system 50 include elimination of cumbersomecabin cluttering tie down straps used on other systems as a result ofthe winch 80 being secured to the support frame 52. Any need to modifythe aft aircraft structure and provide a ramp with 90 degree loweringcapabilities are also eliminated by the system 50. Still further, thesystem 50 has low weight impact on the aircraft in which it is installedbecause fixed provisions are minimal. Also, the construction of thesystem 50 and its component locations enhance the center ofgravity/weight distribution parametric of the aircraft. As can be seenfrom the foregoing description, the system 50 provides a safer crewoperating environment because many of the automated features eliminateshigh risk tasks associated with the previous systems and is less laborintensive. The system 50 also may be easily and rapidly installed andremoved from an aircraft. Still further, the system 50 can befunctionally tested and fine-tuned on the ground prior to aircraftinstallation, resulting in minimum impact on aircraft in-service hours.Multiple mission components, connecting structure and supportinghardware, electronics, and hydraulics can be integrated.

[0033] The system 50 may be used with a helicopter as part of aminehunting system such as that shown in FIG. 5 wherein the externalload 86 is a towed body containing a high resolution, side-looking,multibeam sonar system that is used for minehunting along the oceanbottom.

[0034] The deployment and retrieval system 50 of the present inventionhas been described in the context of a helicopter having a rear dooropening. It should be noted that the system 50, either in the formdescribed above, or in a modified form, may be used with a wide varietyof helicopters and potentially fixed wing aircraft.

[0035] It is apparent that there has been provided in accordance withthe present invention a modular integrated self contained cargodeployment and retrieval system which fully satisfies the objects, meansand advantages set forth hereinbefore. While the present invention hasbeen described in the context of specific embodiments thereof, otheralternatives, modifications, and variations will become apparent tothose skilled in the art having read the foregoing description.Accordingly, it is intended to embrace those alternatives,modifications, and variations, as fall within the broad scope of theappended claims.

What is claimed is:
 1. A system for deploying and retrieving an externalload from an aircraft comprising: a support frame; a winch connected tosaid support frame; a tow cable wound around said winch, said tow cablebeing connected to said external load; and a support structure connectedto said support frame, said support structure being axially movablerelative to said support frame for moving said external load so as tocontrol the center of gravity of said aircraft.
 2. A system according toclaim 1, further comprising means for moving said support structurerelative to said support frame.
 3. A system according to claim 2,wherein said moving means comprises a pair of actuators connected tosaid support structure and to said support frame.
 4. A system accordingto claim 2, further comprising: said support frame having a pair ofspaced apart side rails; each of said side rails having a track; saidsupport structure having a pair of spaced apart side elements; and eachof said side elements having means for engaging and cooperating with oneof said tracks to allow said axial movement of said support structure.5. A system according to claim 4, wherein each said track is formed by alongitudinally extending slot in a respective side rail.
 6. A systemaccording to claim 4, further comprising an energy absorbing memberextending between said side rails, said energy absorbing member actingas a forward crash restraint for said external load.
 7. A systemaccording to claim 4, wherein said support structure further comprises asheave over which said tow cable passes and a support arm extending fromeach of said side elements to support said sheave.
 8. A system accordingto claim 1, further comprising side arms attached to said support frameto support said winch.
 9. A system according to claim 1, furthercomprising control devices mounted to said support frame.
 10. A systemaccording to claim 9, further comprising: said support structureincluding a sheave over which said tow cable passes; and said controldevices including rotational and linear sensors for synchronizing linearmotion of said sheave with motion of said winch.
 11. A system accordingto claim 10, wherein said control devices further comprises at least onevideo camera for monitoring deployment and retrieval of said externalload.
 12. A system according to claim 1, further comprising means forconnecting said support frame to a floor of said aircraft.
 13. A systemaccording to claim 12, wherein said connecting means comprises at leastone of shear and tension connections.
 14. A system according to claim 1,wherein said support frame has a longitudinal axis and said longitudinalaxis is coincident with a center line of said aircraft.
 15. A systemaccording to claim 1, further comprising a removable shield positionedover said support frame.
 16. A system according to claim 1, furthercomprising a barrier in front of said support frame to reduce noise,reduce hazards and control helicopter environment.
 17. A systemaccording to claim 1, further comprising a tow boom pivotably movablerelative to said aircraft.
 18. A system according to claim 17, whereinsaid tow boom is pivotally connected to said support structure.
 19. Asystem according to claim 17, wherein said tow boom includes a pair ofsupport legs and a tow ball capture device connected to said supportlegs.
 20. A system according to claim 19, wherein each of said supportlegs has a first leg portion and a second leg portion connected to saidfirst leg portion by a pivotal connection.
 21. A system according toclaim 20, wherein at least one of said first and second leg portions ofeach of said support legs has a load cell and a yaw sensor incorporatedtherein to provide automatic tow tension indication.
 22. A systemaccording to claim 19, wherein said tow ball capture device includes atow hook and a pyrotechnic cable cutter.
 23. A system according to claim17, further comprising pivotal connections for allowing pivotal movementof said tow boom and a pitch sensor incorporated into each of saidpivotal connections.
 24. A system according to claim 17, wherein saidtow boom is positioned above said external load when said external loadis in a transport mode and said tow boom moves into a rigid trussconfiguration when said external load is being deployed.
 25. A systemaccording to claim 17, further comprising at least one remote videocamera attached to said tow boom for monitoring deployment and retrievalof said external load.
 26. A system according to claim 17, wherein aportion of said tow boom forms an aperture guard for said tow cable. 27.A system according to claim 17, further comprising a containment deviceattached to said tow boom.
 28. A system according to claim 1, whereinsaid system is modular and self-contained.
 29. A method for deployingand retrieving an external load from an aircraft comprising the stepsof: providing a self contained modular deployment and retrieval systemwhich includes a support frame, a winch connected to said support frame,and an axially movable support structure for supporting a sheave;passing a tow cable on said winch over said sheave and connecting an endof said tow cable to said external load; and moving said supportstructure from a retracted position to a deployed position so that theexternal load passes through an opening in said aircraft.
 30. A methodaccording to claim 29, wherein said moving step comprises moving saidsupport structure along an axis coincident with a center line of saidaircraft.
 31. A method according to claim 29, further comprisinglowering said external load to a desired position.
 32. A methodaccording to claim 27, wherein said external load comprises a towed bodyused in a mine hunting operation and said lowering step compriseslowering said towed body into contact with water beneath the aircraft.33. A method according to claim 32, further comprising moving saidaircraft so as to tow said towed body through said body of water.
 34. Amethod according to claim 31, wherein said external load comprises arescue basket and said lowering step comprises lowering said rescuebasket.
 35. A method according to claim 29, wherein said external loadcomprises firefighting equipment and said lowering step compriseslowering said firefighting equipment.
 37. A method according to claim29, further comprising retrieving said external load by winding said towcable onto said winch.
 38. A method according to claim 37, furthercomprising moving said support structure from said deployed position tosaid retracted position after said external load has been aligned withsaid opening in said aircraft.
 39. A method according to claim 37,further comprising providing a tow boom and positioning said tow boomabove said external load when said external load is in a transport mode.40. A method according to claim 39, further comprising pivoting said towboom downwardly into a lockable truss configuration during said externalload lowering step.
 41. A method according to claim 40, furthercomprising capturing said tow cable with said tow boom as said externalload is being lowered.
 42. A method according to claim 40, furthercomprising folding said tow boom as said external load is beingretrieved into said aircraft and moving said folded tow boom to saidposition above said external load.
 43. A helicopter having a fuselageand an opening in said fuselage through which an external load isdeployed, said helicopter comprising: a self contained, modulardeployment and retrieval system secured to said fuselage; and said selfcontained, modular deployment and retrieval system including a supportframe secured to said fuselage and a movable support structure forsupporting a sheave connected to said support frame for movementrelative to said support frame between a retracted position and adeployed position where said external load extends through said opening.44. A helicopter according to claim 43, wherein said support frame has alongitudinal axis and said longitudinal axis is aligned with a centerline of said aircraft.
 45. A helicopter according to claim 43, whereinsaid deployment and retrieval system further comprising a winch attachedto said support frame and said winch having a tow cable which isconnected at one end to said external load and which passes over saidsheave.
 46. A helicopter according to claim 43, wherein said deploymentand retrieval system further comprises a pair of actuators for movingsaid support structure relative to said support frame.
 47. A helicopteraccording to claim 46, wherein said deployment and retrieval systemfurther comprises control devices mounted to said support frame.
 48. Ahelicopter according to claim 43, wherein said deployment and retrievalsystem further comprises: said support frame having a pair of spacedapart side rails; each of said side rails having a track; said supportstructure having a pair of side elements; and each of said side elementshaving means for engaging and cooperating with said track of arespective one of said side rails.
 49. A helicopter according to claim43, wherein said deployment and retrieval system further comprises awinch having a tow cable wound thereon, said tow cable being connectedto said winch and to said external load, and a tow boom for capturingsaid tow cable as said external load is being deployed.
 50. A helicopteraccording to claim 49, wherein said tow boom has a tow hook and apyrotechnic cable cutter.
 51. A helicopter according to claim 49,wherein said tow boom has means for detecting tow tension in said cable.52. A helicopter according to claim 51, wherein said detecting meanscomprises at least one load cell and at least one yaw sensor.
 53. Ahelicopter according to claim 49, further comprising means for detectingthe pitch of said tow boom.
 54. A helicopter according to claim 49,further comprising at least one video camera attached to said tow boom.55. A helicopter according to claim 43, wherein said external loadcomprises a towed body for use in a mine hunting operation.